It's always hard to accept that treating an advanced cancer is difficult and unfavorable.
Your father has stage 4 of pancreatic cancer that has spread to distant organ, liver.
Pancreatic cancer can be controlled only if it is found before it has spread, when it can be removed by surgery. If the cancer has spread, palliative treatment can improve the patient's quality of life by controlling the symptoms and complications of this disease.
Treatment of stage IV pancreatic cancer may include chemotherapy, palliative treatments for pain, palliative surgery or stent placement to bypass blocked areas in ducts or the small intestine and biologic therapy, using the patient’s immune system to fight cancer.
You can, also, get informations about some treatment clinical trial.
I think you'll find this link helpful:
http://www.healthyfoundations.com/pancreat
ic/
Well wishes to you and your family!
Marija